Equipment for building pneumatic tyres

ABSTRACT

A mechanism for building in beads of pneumatic tires on a fixed tire building drum having at least one shoulder, in which there is provided a housing defined by a cylindrical support movable relative to the building drum, levers for compressing the ends of the cord plies against the drum shoulder, and an annular coil spring for turning over the cord ply ends, with the spring being secured on the levers serving to lift the spring. The levers for the compression of the cord ply ends and the lever for lifting the annular coil spring are hingedly secured with the possibility of axial rotation thereof on a common annular carrier or support axially movable relative to the body and the drum. The levers for the compression of the cord ply ends are pressed to the annular coil spring by the axial rotation of the levers with the aid of a template movable by a piston in an air cylinder-piston unit.

ited States atent I Badenkov et al.

[451 Jan. 15, 1974 EQUIPMENT FOR BUILDING PNEUMATIC TYRES Inventors: Petr Fedorovich Badenlkov, prospekt Filed:

Vladimir Alexandrovich Pinegin, deceased, late of Moscow, USSR. by Margarita Vladimirovna Pinegina, administrator June 28, 1971 Appl. No.: 157,493

US. Cl 156/400, 156/132, 156/135,

Int. Cl B29h 17/12, B29h 17/22 Field of Search 156/131, 135, 132,

References Cited UNITED STATES PATENTS Novikov et al. l 56 /4Q0 FOREIGN PATENTS OR APPLICATIONS 1,038,067 8/1966 Great Britain 156/400 1,123,481 8/1968 Great Britain 156/400 Primary Examiner-Clifton B. Cosby Attorney-Holman, Glascock & Seebold [57] ABSTRACT A mechanism for building in beads of pneumatic tires on a fixed tire building drum having at least one shoulder, in which there is provided a housing defined by a cylindrical support movable relative to the building drum, levers for compressing the ends of the cord plies against the drum shoulder, and an annular coil spring for turning over the cord ply ends, with the spring being secured on the levers serving to lift the spring. The levers for the compression of the cord ply ends and the lever for lifting the annular coil spring are hingedly secured with the possibility of axial rotation thereof on a common annular carrier or support axially movable relative to the body and the drum. The levers for the compression of the cord ply ends are pressed to the annular coil spring by the axial rotation of the levers with the aid of a template movable by a piston in an air cylinder-piston unit.

1 Claim, 6 Drawing Figures PATENTEBJAN 1 51974 SHEET 2 BF 3 EQUIPMENT FOR BUILDING PNEUMATIC TYRES The present invention relates to equipment for building pneumatic tyres, namely the mechanisms for building in the beads of pneumatic tyre covers on a fixed tire building drum drum having at least one shoulder.

Known in the prior art are mechanisms for building in the beads of pneumatic tyres, comprising a former for setting the bead core and pressing in the beads, inside said former on the frame of the mechanism there are secured levers for pressing the ends of the cord plies about the drum shoulders, these levers being interconnected by a circular spring and having a pneumatic drive for their reciprocatory movement along the axis of the drum towards the shoulders thereof, levers for lifting a coil spring which articulated thereto are additional levers for distributing the suspending cord plies into folds, an electromechanical drive to actuate the movement of the mechanism for building in the tyre beads relative to the axis of the fixed drum, as well as a pneumatic cylinder to move the levers for lifting the annular coil spring, and a pneumatic cylinder to actuate the movement of the bead former.

In order to build in the tyre beads the ends of the cord plies are clamped between the circular spring of the pressing levers and the coil spring secured on the lifting levers, and interconnecting their ends. The bead former moving along the axis of the building drum interacts with the pressing levers to sink them towards the drum axis. The annular coil spring acted on by the pressing levers sinks as well, so that the cord plies disposed between the pressing and the lifting levers are distributed into folds. Then the pressing levers moving arcwise towards the drum shoulders abut against the cord plies which are thus placed in the recess of the shoulder of the building drum.

At the same time the annular coil spring of the lifting levers performs reciprocatory movement with respect to the tyre bead, in an axial direction relative to the drum.

Next, the bead core is set by means of the bead former, the pressing levers being retracted prior thereto. The levers for lifting the coil spring are moved to turn the cord ply ends over the core.

The prior art mechanism has a disadvantage consisting in that in the course of building in the tyre bead the trajectories of movement of the annular springs of the pressing and the lifting levers do not conform to the profile of the drum shoulder. The divergence between the trajectories of movement of the two interacting annular springs causes incorrect adhesion of the cord to the drum shoulders, which results in a sharp deterioration of the tyre quality.

Employment of different drives pneumatic and electromechanical complicates the pneumoelectrical control system, as well as the design of the tyre building machine as a whole.

In the aforesaid mechanism for building in the tyre head on a fixed tire building drum, the forces to the pressing levers during the pressing operation of the cord plies are transmitted from the core setting former. This calls for pressing levers of a complex profile, as well as for specially made rollers to be mounted inside the core setting former for their interaction with the pressing levers, which results in an early and nonuniform wear of the levers and rollers.

The indicated disadvantages involve a nonuniform clearance between the circular springs of the pressing and the lifting levers along their circumference, nonuniform tension of the cord threads along the circumference of the tyre, and variation of the pressing force value in the course of pressing the cord plies against the drum shoulders.

It is the object of the invention to provide a mechanism for building in the tyre bead on a fixed tire building drum, that would have a simple design, and in which in the process of building in the tyre bead the movement of the pressing levers and the levers for lifting the annular coil spring would conform to the profile of the durm shoulder, and the trajectories of movement of these levers would have no divergences, and besides, a mechanism in which the transmission of force to the pressing levers would be effected without any participation of the core setting former.

With said object in view, a mechanism is provided for building in beads of pneumatic tyre covers on a fixed tire building drum having at least one shoulder, comprising a body defined by a cylindrical support movable relative to the building drum, a former for setting the bead core, and levers for compressing cord plies against the drum shoulders, said levers being provided with a means for axial rotation and pressing them to an annular coil spring serving to turn over the ends of the cord plies and mounted on levers for lifting this annular coil spring, the latter levers being fitted with a drive for their axial swinging, according to the invention, the levers for lifting the annular coil spring and the compressing levers are hingedly secured on a common annular carrier which is axially movable with respect to the body and the building drum.

The means for pressing the compression levers to the annular coil spring should advantageously be made in the form of a pneumatic cylinder whose piston is rigidly secured to a template whose surface supports the ends of the compression levers.

The proposed invention will make it possible to simplify the design of the bead forming mechanism, cut down the time required for building pneumatic tyre covers, simplify the pneumoelectrical remote control system of the mechanism, and facilitate the work of the tyre builder.

The invention is now exemplified with a description of illustrative embodiments thereof and drawings, wherein:

FIG. 11 is a schematic representation of the mechanism for building in beads of pneumatic tyre covers according to the invention, longitudinal section;

FIG. 2 shows the clamping of the cord plies by the levers for compressing the cord ply ends and the levers for lifting the annular coil spring, according to the invention;

FIG. 3 shows the compression of the cord plies against the profile of the tire building drum shoulder, according to the invention;

FIG. 4 shows the setting of the bead core by the former, according to the invention;

FIGS. 5, 6 show the turning of the cord plies over the bead core, according to the invention.

The mechanism for building in beads of pneumatic tyre covers on a fixed tire building drum having at least one shoulder comprises an annular air cylinder 1 (FIG.ll) mounted in a body 2 defined by a cylindrical support, and connected by rods with a pneumatic drive (not shown) of the mechanism for building in tyre beads, which drive serves to move the body 2 relative to the axis of the building drum.

The mechanism also comprises an annular carrier or support 3 movable with respect to the body 2, in the axial direction relative to the drum, by means of an air cylinder I mounted on the body 2. Secured on the annular carrier 3 by pivots 5 are levers 6 for compressing the ends of cord plies 7 against the drum shoulder 8, these levers being radially disposed relative to the drum. Secured as well on the same annular carrier 3 by pivots 9 are levers 10 for lifting an annular coil spring 11 serving to turn over the ends of the cord plies 7. Levers 10 attached to the piston of air cylinder 1 are also disposed in radial directions relative to the drum. Additional levers 12 can be hingedly attached to the levers 10 to fold the ends of the cord plies 7 when pressing them against the drum shoulder 8. The free ends of levers 10 for lifting the annular coil spring 11 rest against the piston of the air cylinder 1 for their swinging about pivots 9.

Located on the annular carrier 3 is an air cylinder 13 whose piston is rigidly connected to a templet 14 or as shown in FIG. 1, a rigid cam surface on which the ends of levers 6 are supported which provides for pressing levers 6 to the annular coil spring 11 at movement of the template 14.

The ends of levers 6 interacting with templet 14 are pulled together by a rubber rope 15. The ends of levers 6 that are pressed to the cord plies 7, are interconnected by coil springs 16 forming a closed annular spring system.

The bead building-in mechanism includes a former l7 fitted with pins 18 serving to place thereon bead cores 19.

Former 17 is connected to a pneumatic drive (not shown) that moves it along the drum axis.

The mechanism for building in beads of pneumatic tyre covers on a fixed building shoulder drum operates as follows:

Air is fed into space A of the pneumatic cylinder 1. The piston of the air cylinder 1 during its motion, turns axially and sets shift levers 10 for lifting the annular coil spring 11 into their working position under the cord plies 7 suspend from shoulder 8 (FIG. 2). When the piston of the air cylinder 13 is in its extreme left position as shown in FIG. 1, levers 6 for compressing the ends of the cord plies 7 are positioned over these suspend ends.

As air is supplied to space B of the pneumatic cylinder l3, templet 14 during its motion performs axial rotation of the levers 6 with the system of coil springs 16 towards the annular coil spring 11 of levers 10. Thus, the ends of the suspending cord layers 7 (FIG. 2) are clamped between spring 11 and springs 16.

The clamping of the ends of the cord plies along the profile of the shoulder of the building drum is performed as follows:

Air is exhausted from space A of the pneumatic cylinder 1, levers 10 for lifting the annular coil spring 11 by moving axially starting to sink. 1

The piston of the air cylinder 13 is moved to the rightmost position, so that the pressing levers 6 supported on their ends on the surface of templet 14 by rotating axially also sink, remaining together with spring 16 pressed against annular coil spring 11.

The sinking of levers 6 can as well be effected by their interaction with former 17 when the mechanism has no templet 14 to cooperate with levers 6.

At the same time, air is supplied to space C of the pneumatic cylinder 4. Its piston moves driving the annular carrier 3 with levers 10, and levers 6 articulated thereon, and the pneumatic cylinder 13 to the extreme left position. At simultaneous movement of the annular support 3 and axial rotation of the levers 6 and 10, with the ends of the cord plies clamped between lever 6 with spring 16 and annular coil spring 11, compression of the ends of the cord plies along the shoulder profile of the building drum is effected. In the course of compression of the ends of the cord plies 7 the trajectories of movement of the annular coil systems of the pressing levers 6 and of levers 10 coincide with each other, and conform to the profile of the drum shoulder 8 (FIGS. 3, 4).

After levers 10 and levers 6 are sunk to their lowermost positions (FIG. 4), former l7 approaches, and the bead core 19 is set.

Then former 17 is retracted to its initial position. Air is let out from space B of the pneumatic cylinder 13 (FIG. 1), and levers 6, one end of which being pulled by the rubber rope 15, being thus lifted.

Air is fed to space A of the pneumatic cylinder 1 to move its piston to the leftmost position. At the same time air is exhausted from space C of the pneumatic cylinder 4. The piston of the pneumatic cylinder 1 moves thus raising levers 10 for lifting the annular coil spring 11, while the annular carrier 3 is being shifted to the rightmost position. The annular coil spring 11 of levers 10 turns the cord plies 7 over core 19 about the profile of the building drum shoulder 8 (FIGS. 5, 6).

The operation of the mechanism has been described for the case of building a single-core tyre. When a double-core tyre is to be assembled on a shoulder drum, the operation of the mechanism is resumed according to the aforedescribed cycle of the assembly process.

The proposed mechanism wherein levers 6 for compressing the ends of the cord plies 7 and levers 10 for lifting the annular coil spring 11 are secured on a common annular carrier 3 movable in an axial direction relative to the body 2 and the building drum, makes it possible to realize the trajectories of movement of the annular springs secured on levers 6 and 10, and clamping the cord plies 7 when following the profile of shoulder 8 of the building drum, which in turn permits formation of the tyre bead by the method of shoulder drum assembly of motor tyres.

In the proposed mechanism, the transmission of force to levers 6 for their sinking can be effected through templet 14, thus obviating the need to use former 17 for this purpose. This involves less wear of the former, simplifies the design of the pressing levers and the former itself, and, inasmuch as the former is used only for core setting, enables setting the core with higher accuracy, thus rasing the quality of the assembled tyres.

In the proposed mechanism, the movement of all the members thereof, and of the mechanism itself, is done by pneumatic drives, which simplifies the design of the tyre building machine as a whole and raises its efficiency.

What we claim is l. A mechanism for building in beads of pneumatic tires, including a fixed building drum having at least one shoulder, a body defined by a cylindrical support movable relative to the building drum, an annular support mounted on the body, first levers for pressing the ends of the cord plies against the at least one shoulder of the building drum, an annular coil spring serving to turn over the ends of the cord plies, second levers serving to lift the annular coil spring, the first and second levers being hingedly connected to the annular support with a possibility of axial rotation thereof, means for pressing the first levers for pressing the ends of the cord plies to the annular coil spring, thereby ensuring clamping of the cord plies between the first levers and the annular coil spring, a pneumatic cylinder-piston unit for effecting axial rotation of the second levers for lifting the annular coil spring, said cylinder being mounted in said body, and a template serving to set the bead core, the template being capable of moving axially relative to the building drum, the improvement that said annular support is movable axially relative to the body and the building drum, so that upon simultaneous movement of the annular support and axial rotation of the first and second levers with the ends of the cord plies clamped between the annular coil spring and the first levers, the ends of the cord plies are compressed along the profile of said at least one shoulder of the building drum, the means for pressing the first levers for pressing the ends of the cord plies against the annular coil spring comprising a further pneumatic cylinder, said further pneumatic cylinder being mounted on said annular support, a piston for the further pneumatic cylinder, and a template rigidly mounted on said last-named piston, the first levers for pressing the ends of the cord plies having ends supported on the surface of the template whereby during movement of the template, the first levers are turned axially and pressed against the annular coil spring. 

1. A mechanism for building in beads of pneumatic tires, including a fixed building drum having at least one shoulder, a body defined by a cylindrical support movable relative to the building drum, an annular support mounted on the body, first levers for pressing the ends of the cord plies against the at least one shoulder of the building drum, an annuLar coil spring serving to turn over the ends of the cord plies, second levers serving to lift the annular coil spring, the first and second levers being hingedly connected to the annular support with a possibility of axial rotation thereof, means for pressing the first levers for pressing the ends of the cord plies to the annular coil spring, thereby ensuring clamping of the cord plies between the first levers and the annular coil spring, a pneumatic cylinder-piston unit for effecting axial rotation of the second levers for lifting the annular coil spring, said cylinder being mounted in said body, and a template serving to set the bead core, the template being capable of moving axially relative to the building drum, the improvement that said annular support is movable axially relative to the body and the building drum, so that upon simultaneous movement of the annular support and axial rotation of the first and second levers with the ends of the cord plies clamped between the annular coil spring and the first levers, the ends of the cord plies are compressed along the profile of said at least one shoulder of the building drum, the means for pressing the first levers for pressing the ends of the cord plies against the annular coil spring comprising a further pneumatic cylinder, said further pneumatic cylinder being mounted on said annular support, a piston for the further pneumatic cylinder, and a template rigidly mounted on said last-named piston, the first levers for pressing the ends of the cord plies having ends supported on the surface of the template whereby during movement of the template, the first levers are turned axially and pressed against the annular coil spring. 